const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
console.log('numbers', numbers)

// * toString
console.log('number.toString()', numbers.toString())

console.log('number.indexOf(10)', numbers.indexOf(10))
console.log('number.indexOf(100)', numbers.indexOf(100))

numbers.push(10)
console.log('push 10: numbers.lastIndexOf(10)', numbers.lastIndexOf(10))
console.log('push 10: numbers.lastIndexOf(100)', numbers.lastIndexOf(100))

const numbersString = numbers.join('-')
console.log('number.join("-")', numbersString)
